<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<title>无标题文档</title>

<style type="text/css">

.layer1{height:100px;}

       .layer1-1{
	width: 30%;
	height: 200px;
	float: left;
	background-color: #F3F;
}

	   .layer1-2{
	width: 40%;
	height: 200px;
	background: blue;
	float: left;
}

	   .layer1-3{
	width: 30%;
	height: 200px;
	background: #FF6;
	float: left;
}
.layer1-4{clear:both}
.layer2{
	height: 300px;
	width: 100%;
	background-color: #0F0;
}

.layer3{
	height: 200px;
	width: 100%;
	background-color: #0FF;
}

</style>

</head>



<body>

<div class=layer1>

  <div class=layer1-1></div>

    <div class=layer1-2></div>

  <div class=layer1-3></div>

   <div class=layer1-4></div>

</div>
<div class=layer2></div>
<div class=layer3></div>
</body>

</html>
